April 16, 2009

Ancient ecosystem found in Antarctica

by Sam Savage

U.S.-led scientists have found that an ecosystem below an Antarctic glacier has survived millions of years by using sulfur and iron compounds for growth.

Co-led by Montana State University Professor John Priscu and Jill Mikucki of Dartmouth College, the scientists said the ecosystem lives without light or oxygen in a pool of brine trapped below Taylor Glacier, next to frozen Lake Bonney in eastern Antarctica.

Priscu said the ecosystem contains a diversity of bacteria that thrive in cold, salty water loaded with iron and sulfur. The water averages 14 degrees Fahrenheit, but doesn't freeze because it is three or four times saltier than the ocean. Since it has been isolated for so long in extreme conditions, the researchers said the ecosystem might explain how life could exist on other planets and serve as a model for how life can exist under ice.

Mikucki said the ecosystem has the potential to be a modern analog to what geochemistry and biogeochemistry was like millions of years ago.

The study that included Peter Lee of the Hollings Marine Laboratory; Ann Pearson, David Johnston and Daniel Schrag of Harvard University; Alexandra Turchyn from Britain's Cambridge University; James Farquhar from the University of Maryland; and Ariel Anbar of Arizona State University appears in the journal Science.